I know this is an old thread just reading about transmissions and noticed this one.the reason the seal changed is that the pump did too,along with the drum under it and i think the band too.all of these parts are avalible through transmission shops or supliers not advance or the others.I have built one of these too it had the same problems with just more miles.Funny how a super charger speeds up the life span of a trans huh.The fix for the 2-4 clutch is to build it with high energy frictions regular steels are ok.The band should be kevlar too.A no yo-yo valebody separator plate will help the aplication of the new frictions and band shifts start off little hard but feel firm later.These mods should be done along with a beafiersun shell,splines slip no reverse.